Adjustable tripod leg



April 11, 1950 1 o. Bu MILLER ADJUSTABLE TRIPOD LEG Filed May 17. 1947 IN VN TOR.

,arme/wey Patented Apr. Il, 1950 y UNITED STAT-Es PATENT oI-Ficsf Leo 0. Bu Miller, Van Nuys, Calif, assigner to Eiliward` H. Hopkins, Los Angeles, Calif..

spniieanen May 17, 1941;, sensing. 748,756

This invention .relates to an yanchoring device for' adjustably positioning two telescoping members with respect to each other, and more particularly, but not necessarily, to radjustable tripod legs.

" Much diiilculty is -experiencedin leveling tripods used for supporting -carneras,'surveying iinstruments andthe like. due to the irregularities of the supporting Isurface on which i-tis frequently required to position thesedevices. Usually, the legs vare pivotally'mounted rat their top to the body of the tripod `in order that 'they may be positioned at various angles to' the per-- vpendicular, and arranged for longitudinal exten- [sion by arrangements of slidable members kwlriieh may be clamped 'together byA means of `thu-nib screws or other clamping means. The clamping means, such as thumb screws usually employed for clamping the telescopic type of leg,vis objecv tionable due tothe thumb screw projecting outwardly and contacting elements which often loosen the screws and causethe leg orf legs to become loose. `In addition the clamping memf bers are bulky and often mar and damage the leg elements. It is, therefore, a primary Aobject 'ofithis Vinvention 'to provide a novel means for anchoring two 'telescopic members with respect to each other, wherein the anchoring means'is located entirely the couter telescopic member.

Another object is to provide an anchoring means for two telescopic members that may be actuated by relative rotation of one member with respect to the other.

A further object is to provide an anchoring device for adjustably positioning two telescopic members that will be simple in structure, durable, efficient in operation and comparatively cheap to manufacture.

A further object is to provide anchoring means "for two telescopic members that will positively 1 claim. (c1. esi-5s) Fig.. 1 .is a side elevation view of 'a tripod. zem bodying `the invention.

Fig. 2. -is a vertical .sectional View of one of the tripod legs embodying the invention.

Fig. 3 is an .enlarged fragmentary .sectional view of the anchoring means in normal .released position` I Fig. 4 is a viewv similar' 3... showing the device Sin locked or anchored position. Reerrmg to the drawings the numeral. III .indicatesfthe headsof a tripod having three legs, each leg represented in its entirety by II. The 'legs 'I t maybe lconnected at their tops by rany.fsuit :able meanssnchas shown at l5.

f Each' ci the legs 'Il consists of :an outer :and lupper tubular member I2. an inne-r.7 lower member .I3 which may be tubular or solid, as desired. 'In any event. the .inner member is provided with a head portion I4 through which an axially -disposed threaded bore t6; is provided vfor receiving and supporting an means represented in its entirety by Il.

The means i] consists of a-compresy :sible resilient I-.8 `which may be .madeoi rubber. Theannulus I8 is provided with a eenltrai .bore y axial alignment with. the threaded bore `I6 inthe head if( of the inner ,membert Lower and upper pressure plates,` I9 and 2l re.y .spectirely rest againstthe lower and upper sur vfaces ofy the annulus lo; each or these pressure plates, 19t-and 2 If, being provided with` axial openn ings. in .alignment with 'the :openings :2.0l the anrnilns Il and` the.` kthreaded` ,opening I6 in the head I 4 of the inner member I3. A threaded member 22, having a head portion 23, extends through the opening in the pressure plate 2l, annulus I8, pressure plate I9, and is threaded into the threaded opening I6 whereby upon turning the inner member clockwise the threaded opening' I 6 cooperating with the threaded member 22 will operate to draw the head 23 downwardly and into contact with the upper face of the pressure plate 2l, while simul- Y taneously the upper end of the inner member I3 will contact the lower face of the pressure plate I 9, and as the member I3 is rotated the threaded member 22 will cause the pressure plates I9 and '2| to compress the annulus I8 into pressure con? tact with the inner walls of the outer member I2. thereby anchoring the members I3 and I2 into fixed relation.

The external diameter of the cylinder or annulus I8 is substantially equal tothe internal diameter of member I2, so that when such element I8 is uncompressed some force is required to fric-l The ratio of diameter to height of the resilient, i y elastic annulus may vary; when height exceeds diameter a greater force is needed to slidably adjust the members, but upon expansion of the annulus a larger gripping surface'1 is engaged. `l

The inner member I3 may be-slightly smaller in external diameter than the inner .diameter of the outer member I2 and the lower end of the the device is comparatively cheap to manufacture as Well as attractive in appearance.

The adjustable anchoring construction, although shown embodied in a tripod. may be used in less of various forms of furniture (such as card tables etc.) in towel rack arms, camp tent poles, and wherever longitudinal extension and retraction is desired. While I have illustrated and described a single form ofi the Vpresent invention, it will be apparent t0 those skilled in-the art that certain changes, substitutions, additions and modications may be made in the exemplary form shown without departing from the spirit and scope nof the appended claim.

member I2 being reduced as shown at 24'to sliclably receive the inner member I3. In this construction, as illustratedxbyv thedrawings, the members I2 and I3 are in clo'se'contact at the botl` tom of the outer member I2 and the point of con- 'fior a rigid substantial connection.

When it is desired t0 adjust the members I2 `and I3 relative to each other; it is only necessary to rotate the inner member VI3 counterclockwise `with respect, t0 member I2 for releasing the pres'- .sure plates I9 and 2| from theannulus I8 and slide the members I2 and I3 longitudinally with respect to each other to provide the length 0f the leg or other member as may be required. After adjusting the member I2 and I3, the member I3 is then rotated clockwise with respect to member -I2 and clamping the pressure plates to expand the annulus into` holding contact with the outer member. The inner Ymember may be tubular -a'nd provided at its lower end with rubber 0r other suitable feet 25 inserted therein or the inner member may be solid and suitablesfeet attachedto its lower end by any suitable means such as an axial recess. ..11- I 'iA-The present devide'is simple instructure, eni- Icient 'in' operation; Sandi' the anchoring means4 is entirely yconcealed.within the outertelescopical members. Also, the' deviefmay be .readily and easily operated by merely rotating thelinner member with respectl to the Souter member and.. adjusted at the will of thef'op'erator vwithout the 'assistance of tools or projections, and, further,

I Ananchoring device for adjustably positioning two telescoping` members with respect to each otherincluding an inner cylindrical telescoping member provided with a smooth outer surface of uniform diameter, an outer telescoping member including a bore adapted to slidably receive the said inner member, an internally threaded axial bore in one end of the inner member, a headed element provided with a threaded shank in engagement with the internally threaded bore, a cylindrical annulus of resilient rubber composition v frictionally mountedupon lthe shank of the REFERENCES CITED rhe following. references are of record in the file 0f this patent:

UNITED STATES PATENTS Number 4 Name i .Date

663,804 Bilder Dec. 11, 1900 g 2,298,380 Hoed 1 jt l `oct. 13, 1942 l FOREIGN PATENTS l,

Number Country Date 

